Dunnage



Dec. 3, 1968 J. G, FELDKAMP 3,414,140

DUNNAGE Filed Aug. l, 1966 United States Patent A O 3,414,140 DUNNAGEJohn G. Feldkamp, Homewood, Ill., assignor to Interlake SteelCorporation, Chicago, Ill., a corporation of New York Filed Aug. 1,1966, Ser. No. 569,358 11 Claims. (Cl. 214-105) ABSTRACT OF THEDISCLOSURE A pneumatic dunnage device for cushioning a load in atransportation vehicle. The device has a flexible inflatable bladdercovered with a reinforcing shroud and the bladder is provided with valvemeans to permit ination of the device. A reinforcement patch is providedon the bladder wall opposite the position of the valve means forstiifening the bladder in the region of the patch to minimize weakeningofthe bladder in that region due to forces on the bladder caused byinrushing air when the device is inflated through the valve means.

This invention relates to the art of shoring merchandise andparticularly to an improved shoring or dunnage device.

Patent No. 3,199,689, issued to John G. Feldkamp on Aug. 10, 1965, showsand describes an inflatable resilient bag-type device for use as ashoring or dunnage device for merchandise shipped in a transportationvehicle, provided with an inner plastic bag acting as a bladder or aircontaining member aand outside strength providing layers of relativelystrong and inexpensive materials, such as burlap, sisal, rayon, andpaper. The use of inexpensive construction materials for the dunnagedevice provides sufficient economy to permit it to be discarded after asingle use, even though it is durable enough for limited repeated use.

Experience with the type of dunnage device described in the patent hasrevealed a certain diiculty during its ination. When the device is in aflattened condition preparatory to use, the wall of the plastic bladdercontaining the inflating valve is closely adjacent to the opposite wallof the bladder. As pressurized -air is introduced through the valve,portions of the wall of the bladder opposite the valve and portions ofthe wall containing the valve proximate to the edge of the base of thevalve are strained due to the forces of the in-rushing pressurized air.This is accompanied by vibration as evidenced by a high pitched sound.When the bladder is of polyethylene plastic, these forces may seriouslystr-ain and weaken the plastic to such an extent that holes are-oftentimes produced, thereby destroying the utility of the dunnagedevice.

It is the principal object of this invention to improve the constructionof such a dunnage device by employing reinforcing means on the bladderwall in the vicinity of the affected portions in order to stiffen theportions and minimize the undesirable effects which damage the device.

In order to achieve this objective, it is still another object to employa stiffening patch on the inside surface of the bladder portions, saidpatch providing an inexpensive and simple expedient for this purpose.

It is still another object to provide such a patch which is ofinexpensive fabric or paper material covered with a pressure sensitivecoating to enable it to be readily applied to the bladder.

Other objects and advantages of the invention should be apparent uponreference to the accompanying drawings in which:

FIG. l shows a perspective view of an embodiment of an inflated shoringor dunnage device manufactured according to this invention;

3,414,140 Patented Dec. 3, 1968 ice FIG. 2 shows a perspective view ofthe shoring or dunnage device of FIG. l in its deflated condition;

FIG. 3 shows a plan view of the shoring or dunnage device in itsdeflated position;

FIG. 4 is a left side view of the dunnage device of FIG. 3;

FIG. 5 is a sectional view along the line 5-5 of FIG. 3 and shows therelationship of the various wall layers of the dunnage device, the valvemeans yfor inflation, and the reinforcing means which substantiallyeliminates vibration of portions of the bladder;

FIG. 6 shows an open tube of plastic Whic-h, when sealed, forms theplastic bladder used Within the device of FIGS. l and 2; and

FIG. 7 shows an airtight plastic bladder embodying the improvement ofthis invention.

As shown particularly in FIGS. 6 and 7, the plastic bladder or aircontaining member 2 used inside the device 1 may be made from a tube 2aof high density polyethylene plastic compounded with butyl-rubber (suchas Grax Plastic Co., Division of Allied Chemical Co., Clifton, NJ.,compound number 2201) of -an average thickness of six thousandths of aninch and a minimum thickness of about fifty-four ten thousandths (.0054)of an inch. The plastic tube 2a may be cut to size and a reinforcementmeans such as a square patch of heavy duty pressuresensitive tape can beinstalled on the inside surface of the plastic tube 2a as shown in FIG.6. An air valve 4 can be heat sealed at its base 9 to the inside surfaceof the plastic tube 2a. The tube 2a is then flattened into a doublelayer condition such that the valve 4 lies directly adjacent andopposite to the reinforcement means 7. Both the forward end 2b and therear end 2c of the plastic tube 2a are then heat sealed together -alonglines 2d and 2e, respectively. With these ends 2b and 2c sealed, theflattened tube is in the shape of a flat enclosure which is, then, anairtight bladder.

Six plies of extensible kraft paper, the outer ply of which can bewaterproofed with polyethylene, are then made into a single multi-walledpaper tube 3 by overlapping the two edges of each ply which are gluedtogether as indicated at 3a. The paper tube 3 is cut to a length longerthan that of the bladder 2.

The airtight plastic bladder 2 is then carefully inserted into thecut-to-length paper tube 3 so that there are no objectionable wrinklesor creases formed in the bladder and such that the valve 4 and thereinforcement patch 7 remain adjacent. The air valve 4 is passed throughthe central opening 10 of an annular grommet 4c secured to the annularmargins of a corresponding opening of the paper plies of tube 3 toprovide access to the valve externally of the device. A resilient tightfitting metal fastener 4b is pressed down over an annular notch 4daround the projecting portion of the valve 4 to keep its base 9 urgedtoward the grommet 4c and fully projecting.

With the reinforcing plies of the multiwall paper tube 3 enveloping thebladder 2, dowel rods y6 and 11 are placed at the ends of the paper tube3 at regions adjacent the end seals 2d and 2e of the bladder 2. Thesuperimposed layers of the plies of paper of the tube 3 and the walls ofthe plastic bladder Z are then folded around the dowel rods 6 and 11.Metal edges or end closures 5 and 12 `are then positioned around theportions surrounding the dowel rods 6 and 11. The end closures arepreferably tightly squeezed by means of a press to insure a tight gripof the end closures 5 and 12 on the device. This tightening is indicatedin FIG. 5 by the movement of the end closure 5 and the bag portions frompositions shown in dotted lines to those shown in solid outline.

When the dunnage device 1 is in its iinal assembled form as shown inFIG. 2, it is then lled with air through the valve 4 to a suitablepressure of about four pounds per square inch for ordinary use.

The inflating valve 4 consists of a pin or plunger 13, an annular rubberwasher 15 which is secured to the base of the pin 13 by fitting the'Washer 15 partly into a groove at the pin base, and a spring 14 whichforces the pin 13 toward the free end of the valve, thereby forcing thewasher 15 against an annular projection 16 of the inside valve wall. Acap plug 17 can be secured on the valve to protect the pin 13 fromaccidental displacement which can cause air leakage. To inflate thedunnage device, the cap plug 17 is removed from the valve 4 and a sourceof pressurized air is applied to the valve. Pin 13 is forced downward bythe air pressure, providing an opening between the washer 15 and theprojection of the valve Wall 16 which permits access of the pressurizedair through the valve base 9 to the plastic bladder 2. When the dunnagedevice 1 is filled to suflicient pressure, the pressurized air source isremoved from the valve. The spring 14 forces return of the pin 13 toforce the washer 15 against the annular projection 16 L of the innervalve wall, thereby blocking the then pressurized air inside the dunnagedevice 1 from escaping.

It is during the inflation process that the need of the reinforcementmeans 7 exits. As best seen in FIG. 5, prior to inflation, one wall ofthe plastic bladder 2, as indicated in solid outline, is ordinarilypositioned directly against the base of the air valve 4. Because therelatively thin gauge plastic bladder 2 is not ordinarily attached(except at the ends of the device) to the inner ply of the paper tube 3,it is ordinarily free to be strained as a result of the incoming streamof high pressure air. Without the patch 7 or other reinforcing means,the forces of the inrushing pressurized air stream oftentimes strain thebladder walls and weaken them sufficiently to rupture the plasticbladder in the regions proximate to the valve to render the dunnagedevice useless Without its air retaining ability. By installing thereinforcing means 7 made of heavy duty pressuresensitive tape or paper,for example, on the inner wall of the plastic bladder 2 directlyopposite the valve 4, the deleterious effect of the forces of theincoming pressurized air can be substantially eliminated,

The dunnage devices described are generally manufactured in varioussizes from widths of 36 inches to 47 inches and lengths of 70 inches to118 inches. The valve 4 described may be of one standard size for allsizes of dunnage devices. The base 9 of the valve may consist of anannulus with an outside diameter of approximately 2 inches and insidediameter of approximately 1/2 inch corresponding to the diameter of theair inlet of the valve.

To eliminate the deleterious condition, various sized reinforcingpatches can be incorporated. For example, it has been found that a patchwhich at least covers the annular base 9 of the valve 4 and which can belarger than the base 9 by any amount will satisfactorily minimize thecondition. A patch of 4 by 4 inches is satisfactory for the valve 4having an annular base 9 with the 2 inch outside diameter and 1/2 inchinside diameter.

I claim:

1. A pneumatic dunnage device for cushioning a load in a transportationvehicle comprising, a longitudinally extending, substantially flat firsttube of relatively thin, flexible, synthetic, thermoplastic filmmaterial for providing a discrete inflatable, airtight bladder, alongitudinally extending, substantially flat second tube of strongflexible paper, said second tube containing said first tube, a lateralreinforcing strip at each end extremity of said second tube, meanssecuring together the opposite walls of said second tube and saidreinforcing strips at the respective opposite ends of said second tube,and valve means on said first tube extending through the wall of saidsecond tube and to the exterior thereof, said first tube beinginflatable through said valve means, said second tube being of a sizeand the paper being of suflicient strength to provide reinforcingbacking for all portions of said first tube, when the latter isinflated, to prevent rupture of said first tube when said dunnage deviceis subjected to impacts from the load, the flexibility of said paper ofsaid second tube permitting said second tube to balloon outwardly inresponse to pressure in said first tube as it is inflated, andreinforcing means on the inside surface of the first tube positioneddirectly opposite the location of the valve means, said reinforcingmeans providing a stiffener for minimizing weakening of the portions onthe first tube in regions proximate to the valve means due to the forceson the first tube by the inrushing air when the first tube is beinginflated through the valve means.

2. A pneumatic dunnage device for cushioning a load in a transportationvehicle as defined by claim 1 characterized by, said reinforcing meansbeing in the form of a flexible patch adhered to the inside surface ofthe first tube.

3. A pneumatic dunnage device for cushioning a load in a transportationvehicle as defined by claim 1 characterized by, said reinforcing meansbeing in the form of a flexible and strong patch adhered to the insidesurface of the first tube by pressure sensitive means.

Y4. A pneumatic dunnage device for cushioning a load iny atransportation vehicle comprising, a flat inflatable bladder ofrelatively flexible airtight film material, a flat shroud of strongflexible material enveloping said flat bladder and providing apillow-shaped reinforcing backing for all portions of the bladder whenthe bladder is inflated to a pillow shape, valve means on said bladderextending through the wall of the shroud and to the exterior thereof,said bladder being inflatable through the valve means, and otherreinforcing means on the inside surface of the bladder confined to aposition opposite the location of the valve means and ordinarily inclose proximity to the valve means when the bladder is in its flatcondition, said other reinforcing means providing a stiffener for thebladder in the region of its position on the bladder for minimizingWeakening of the portions of the bladder in regions proximate to thevalve means due to the forces on the bladder caused by the inrushing airpassing between the valve portion of the bladder and the otherreinforcing means in close proximity thereto when the bladder is beinginflated through the valve means.

5. A pneumatic dunnage device for cushioning a load in a transportationvehicle as defined by claim 4 characterized by, the valve means having ahollow elongated substantially cylindrical body with a central borethrough which the inflating air passes, a relatively rigid annulusextending radially outward from the base of the valve, said annulusbeing joined by an airtight connection to one wall portion of thebladder, said reinforcing means positioned opposite the location of thevalve means being of an area large enough to substantially extend overthe entire area of the annulus when the dunnage device is in itsflattened and deflated condition.

6. A pneumatic dunnage device for cushioning a load in` a transportationvehicle as defined by claim 4 characterized by, the valve means having abase stiffer than the film material of the bladder extending radiallyoutward from the valve, said base being joined by an airtight connectionto one wall portion of the bladder, said reinforcing means positionedopposite the location of the valve means being of an area large enoughto substantially extend over the entire area of the base when thedunnage device is in its flattened and deflated condition.

7. A pneumatic dunnage device for cushioning a load in a transportationvehicle comprising, a flat inflatable bladder of relatively flexibleairtight film material, a shroud of strong flexible material envelopingsaid bladder and providing a reinforcing backing for all portions of thebladder when the bladder is inflated, valve means on said bladderextending through the Wall of the shroud and to the exterior thereof,said bladder being inflatable through the valve means, and reinforcingmeans on the inside surface of the bladder opposite the location of thevalve means, said reinforcing means providing a stiffener for minimizingweakening of the portions of the bladder in regions proximate to thevalve means due to the forces on the first tube by the inrushing airwhen the bladder is being inflated through the valve means saidreinforcing means being in the form of a flexible patch adhered to theinside surface of the bladder.

8. A pneumatic dunnage device for cushioning a load in a transportationvehicle comprising, a flat inflatable bladder of relatively flexibleairtight film material, a shroud of strong flexible material envelopingsaid bladder and providing a reinforcing backing for all portions of thebladder when the bladder is inflated, valve means on said bladderextending through the wall of the shroud and to the exterior thereof,said badder being inflatable through the valve means, and reinforcingmeans on the inside surface of the bladder opposite the location of thevalve means, said reinforcing means providing a stiffener for minimizingweakening of the portions of the badder in regions proximate to thevalve means due to the forces on the first tube by the inrushing airwhen the bladder is being inflated through the valve means, saidreinforcing means being in the form of a flexible and strong patchadhered to the inside surface of the bladder by pressure sensitivemeans.

9. A pneumatic dunnage device for cushioning a load in a transportationvehicle comprising, a flat inflatable bladder of relatively flexibleairtight film material, a shroud of strong flexible material envelopingsaid bladder and providing a reinforcing backing for all portions of thebladder when the bladder is inflated, valve means on said bladderextending through the wall of the shroud and to the exterior thereof,said bladder being inflatable through the valve means, and reinforcingmeans on the inside surface of the bladder opposite the location of thevalve means, said reinforcing means providing a stiffener for minimizingweakening of the portions of the bladder in regions proximate to thevalve means due to the forces on the first tube by the inrushing airwhen the bladder is being inflated through the valve means, saidreinforcing means being in the form of a flat disc-shaped patch adheredto the inside surface f the bladder to effectively thicken the wall ofthe bladder in the region of the patch.

10. In an airtight pneumatic bladder of relatively flexible airtightmaterial in the form of a tube which can be flattened with two oppositewall portions of the tube in close proximity to each other, one of saidwall portions having a valve means through which the bladder can beinflated, comprising, a reinforcing means on the second of the two wallportions confined to a location opposite that of the valve means andordinarily in close proximity to the valve means whenithe bladder isflattened, said reinforcing means providing a stiffener for the bladderin the region of its position on the bladder for minimizing weakening ofthe portions of the bladder in the regions proximate to the valve meansdue to the forces on the bladder caused by the inrushing air passingbetween the valve portion of the bladder and the reinforcing means inclose proximity thereto when the bladder is being inflated through thevalve means.

11. A pneumatic dunnage device for cushioning a load in a transportationvehicle comprising, a longitudinally extending, substantially flat firsttube of relatively thin, flexible, synthetic, thermoplastic filmmaterial for providing a discrete inflatable, airtight bladder, alongitudinally extending, substantially flat second tube of strongflexible paper, said second tube containing said first tube, said firstand second tubes being closed at their ends, and valve means on saidfirst tube extending through the wall of said second tube and to theexterior thereof, said first tube being inflatable through said valvemeans, said second tube being of a size and the paper being ofsuflicient strength to provide reinforcing backing for all portions ofsaid first tube, when the latter is inflated, to prevent rupture of saidfirst tube when said dunnage device is subjected to impacts from theload, the flexibility of said paper of said second tube permitting saidsecond tube to balloon outwardly in response to pressure in said rsttube as it is inflated, and reinforcing means on the first tubepositioned directly opposite the location of the valve means andordinarily in close proximity to the valve means when the first andsecond tubes are in their fiat conditions, said reinforcing meansproviding a stiffener for the first tube in the region of its positionon the first tube for minimizing weakening of the portions on the firsttube in regions proximate to the valve means due to the forces on thefirst tube by the inrushing air passing between the valve portion of thefirst tube and the reinforcing means in close proximity thereto when thefirst tube is being inflated through the valve means.

References Cited UNITED STATES PATENTS 2,207,212 7/ 1940 Arey 137-223 XR2,297,994 10/ 1942 Vellinga 15 0-9 XR 2,601,568 6/ 1952 Sussenbach et al229-65 3,199,689 8/ 1965 Feldkamp 214-10.5

GERALD M. F ORLENZA, Primary Examiner. F. E. WERNER, Assistant Examiner.

